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A 30-year-old young previously healthy man presented to our hospital with middle and upper abdominal discomfort. Abdominal computerized tomography (CT) showed no significant abnormalities. White light endoscopy showed the local mucosa in the descending part of the duodenum had granuloid uplift, some of which were fused into pieces with red color, and some other areas showed fading tone. Magnifying endoscopy with indigo-carmine staining and narrow-band imaging showed a finger-like, loose villous structure with irregular microvessels on the surface. Pathological examination of biopsy specimens showed that lymphocytes were diffused and dispersed in the mucosa with relatively simple morphology, no lymphoid follicles were observed, and local compression was obvious. Immunohistochemical staining revealed a lymphoid population highly positive for CD20 and CD10. These results were consistent with duodenal-type follicular lymphoma (D-FL).
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Neoplasias Duodenais , Linfoma Folicular , Masculino , Humanos , Adulto , Neoplasias Duodenais/diagnóstico por imagem , Neoplasias Duodenais/cirurgia , Duodeno/diagnóstico por imagem , Duodeno/patologia , Endoscopia Gastrointestinal , Linfoma Folicular/diagnóstico , Linfoma Folicular/patologiaRESUMO
Antithrombin III is an important anticoagulant factor with anti-inflammatory properties. However, few studies have explored its anti-inflammatory actions in ATIII overexpressed transgenic animals. In this study, the dairy goats with mammary overexpression of ATIII were used to investigate their general health, milk quality and particularly their response to inflammatory challenge. The results showed that transgenic goats have a normal phenotype regarding their physiological and biochemical parameters, including whole blood cells, serum protein levels, total cholesterol, urea nitrogen, uric acid, and total bilirubin, compared to the WT. In addition, the quality of milk also improved in transgenic animals compared to the WT, as indicated by the increased milk fat and dry matter content and the reduced somatic cell numbers. Under the stimulation of an LPS injection, the transgenic goats had elevated contents of IGA, IGM and superoxide dismutase SOD, and had reduced proinflammatory cytokine release, including IL-6, TNF-α and IFN-ß. A 16S rDNA sequencing analysis also showed that the transgenic animals had a similar compositions of gut microbiota to the WT goats under the stimulation of LPS injections. Mammary gland ATIII overexpression in dairy goats is a safe process, and it did not jeopardize the general health of the transgenic animals; moreover, the compositions of their gut microbiota also improved with the milk quality. The LPS stimulation study suggests that the increased ATIII expression may directly or indirectly suppress the inflammatory response to increase the resistance of transgenic animals to pathogen invasion. This will be explored in future studies.
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Antitrombina III , Lipopolissacarídeos , Animais , Feminino , Lipopolissacarídeos/farmacologia , Antitrombina III/metabolismo , Leite/química , Animais Geneticamente Modificados , Anticoagulantes/farmacologia , Cabras/genética , Nível de Saúde , Glândulas Mamárias Animais/metabolismo , LactaçãoRESUMO
A 77-year-old male underwent gastroscopy in our institution. Conventional endoscopic examination revealed two ectopic gastric mucosas (EGMs) located about 17cm from the incisors. One of the EGMs was about 0.6cm in size and was round with a flat surface and a slight uplift in the center. The boundary of the uplift was clear and the villous structure disappeared. Narrow Band Imaging (NBI) showed irregular microvessels with a fine network pattern at the uplift, and there appeared to be small and punctate crypt opening (CO) in the glandular ducts. Then we performed acetic acid staining and found that the lesion showed dense and small CO clearly, suggesting differentiated gastric cancer. Histopathologic diagnosis of the biopsy specimen from the lesion was high-grade intraepithelial neoplasia.
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Carcinoma in Situ , Neoplasias Gástricas , Masculino , Humanos , Idoso , Esôfago/patologia , Gastroscopia/métodos , Carcinoma in Situ/diagnóstico por imagem , Carcinoma in Situ/patologia , Neoplasias Gástricas/patologia , Imagem de Banda Estreita/métodos , Mucosa Gástrica/patologiaRESUMO
A 47-year-old man developed recurrent bloating. First gastroscopy showed there was a fading lesion about 0.5cm in size near the anterior wall of the large curve of the junction of the gastric antrum and the edge was red, and the biopsy pathology showed signet ring cell carcinoma (SRC). Subsequently, he went to other hospital for endoscopic submucosal dissection (ESD). However, postoperative pathology indicated inflammation. After 6 months, gastroscopy showed that the lesion size was similar to that of the first time, the fading was obvious, and no redness was observed. Another year later, the lesion size was not significantly changed from these before. Weak amplification of Narrow Band Imaging (NBI) showed slight dilatation of the glandular duct, mainly fading, no redness, and the biopsy was still SRC. Finally, he received a second ESD, and the postoperative pathology was consistent with that of our results.
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BACKGROUND: Autosomal dominant polycystic kidney disease (ADPKD) is a prevalent genetic disorder, mainly characterized by the development of renal cysts, as well as various extrarenal manifestations. Previous studies have shown that ADPKD is related to bronchiectasis, while its pathogenic mechanism is unclear. In previous studies, we have generated the PKD1+/- pigs to simulate the progression of cyst formation and physiological alterations similar to those seen in ADPKD patients. METHODS: Phenotypic changes to airway epithelial cell and mesenchymal cell in PKD1+/- pigs were assessed by histological analysis. The molecular mechanisms driving these processes were investigated by using PKD1+/- pig lungs, human mesenchymal cells, and generating PKD1 deficient human epithelial cells. RESULTS: We identified bronchiectasis in PKD1+/- pigs, which is consistent with the clinical symptoms in ADPKD patients. The deficiency of PKD1 suppressed E-cadherin expression in the airway epithelial barrier, which aggravated invasion and leaded to a perpetuated inflammatory response. During this process, extracellular matrix (ECM) components were altered, which contributed to airway smooth muscle cell phenotype switch from a contractile phenotype to a proliferative phenotype. The effects on smooth muscle cells resulted in airway remodeling and establishment of bronchiectasis. CONCLUSION: To our knowledge, the PKD1+/- pig provides the first model recapitulating the pathogenesis of bronchiectasis in ADPKD. The role of PKD1 in airway epithelial suggests a potential target for development of new strategies for the diagnosis and treatment of bronchiectasis.
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Bronquiectasia , Rim Policístico Autossômico Dominante , Humanos , Suínos , Animais , Rim Policístico Autossômico Dominante/genética , Rim Policístico Autossômico Dominante/metabolismo , Rim Policístico Autossômico Dominante/patologia , Canais de Cátion TRPP/genética , Canais de Cátion TRPP/metabolismo , Bronquiectasia/genética , Células Epiteliais/metabolismo , Pulmão/metabolismo , MutaçãoRESUMO
Melatonin is a natural molecule produced in the pineal gland and other tissues. It participates in numerous biological activities including the regulation of reproduction. However, the mechanism by which melatonin affects mammalian female reproductive performance is not fully investigated. In the present study, it was observed that melatonin positively regulated the level of leptin in female mouse and pig. To understand the potential association between melatonin and leptin on the female reproductive activities, the melatonin receptor 1 MT1 knockout (MT1-/- ) mouse and Leptin knockout (Leptin-/- ) pig were created. It was found that the deficiency of M T1 caused low leptin secretion and litter size in mouse. Meanwhile, the deletion of leptin in pig did not affect melatonin production, but significantly reduced follicle-stimulating hormone, estradiol-17ß (E2), and Luteinizing hormone and increased progesterone (P) at estrum stage, which also led to smaller litter size than that in control. Melatonin treatment increased the production of leptin in pigs, while the supplementary of leptin was also able to improve the ovulation number, polar body rates, and expression of StAR in MT1-/- females. Therefore, it is first time, we described that leptin is the downstream target of melatonin in regulating female reproduction. These findings provide the novel information on the physiology of melatonin in animal reproduction.
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Leptina/metabolismo , Melatonina/metabolismo , Animais , Feminino , Técnicas de Inativação de Genes , Camundongos , Receptor MT1 de Melatonina/metabolismo , Reprodução/fisiologia , SuínosRESUMO
Pten is a multifunctional tumor suppressor. Deletions and mutations in the Pten gene have been associated with multiple forms of human cancers. Pten is a central regulator of several signaling pathways that influences multiple cellular functions. One such function is in cell motility and migration, although the precise mechanism remains unknown. In this study, we deleted Pten in the embryonic lung epithelium using Gata5-cre mice. Absence of Pten blocked branching morphogenesis and ERK and AKT phosphorylation at E12.5. In an explant model, Pten(Δ/Δ) mesenchyme-free embryonic lung endoderm failed to branch. Inhibition of budding in Pten(Δ/Δ) explants was associated with major changes in cell migration, while cell proliferation was not affected. We further examined the role of ERK and AKT in branching morphogenesis by conditional, endodermal-specific mutants which blocked ERK or AKT phosphorylation. MEK(DM/+); Gata5-cre (blocking of ERK phosphorylation) lung showed more severe phenotype in branching morphogenesis. The inhibition of budding was also associated with disruption of cell migration. Thus, the mechanisms by which Pten is required for early endodermal morphogenesis may involve ERK, but not AKT, mediated cell migration.
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Endoderma/embriologia , Endoderma/enzimologia , Pulmão/embriologia , Sistema de Sinalização das MAP Quinases , Morfogênese , PTEN Fosfo-Hidrolase/metabolismo , Animais , Movimento Celular , Epitélio/metabolismo , MAP Quinases Reguladas por Sinal Extracelular/metabolismo , Fator de Transcrição GATA5/metabolismo , Deleção de Genes , Integrases/metabolismo , Camundongos , Modelos Biológicos , Especificidade de Órgãos , Fosforilação , Proteínas Proto-Oncogênicas c-akt/metabolismoRESUMO
Development of the mammalian lung is predicated on cross-communications between two highly interactive tissues, the endodermally derived epithelium and the mesodermally derived pulmonary mesenchyme. While much attention has been paid for the lung epithelium, the pulmonary mesenchyme, partly due to lack of specific tractable markers remains under-investigated. The lung mesenchyme is derived from the lateral plate mesoderm and is the principal recipient of Hedgehog (Hh) signaling, a morphogenetic network that regulates multiple aspects of embryonic development. Using the Hh-responsive Gli1-cre(ERT2) mouse line, we identified the mesodermal targets of Hh signaling at various time points during embryonic and postnatal lung development. Cell lineage analysis showed these cells serve as progenitors to contribute to multiple lineages of mesodermally derived differentiated cell types that include parenchymal or interstitial myofibroblasts, peribronchial and perivascular smooth muscle as well as rare populations of cells within the mesothelium. Most importantly, Gli1-cre(ERT2) identified the progenitors of secondary crest myofibroblasts, a hitherto intractable cell type that plays a key role in alveolar formation, a vital process about which little is currently known. Transcriptome analysis of Hh-targeted progenitor cells transitioning from the pseudoglandular to the saccular phase of lung development revealed important modulations of key signaling pathways. Among these, there was significant downregulation of canonical WNT signaling. Ectopic stabilization of ß-catenin via inactivation of Apc by Gli1-cre(ERT2) expanded the Hh-targeted progenitor pools, which caused the formation of fibroblastic masses within the lung parenchyma. The Gli1-cre(ERT2) mouse line represents a novel tool in the analysis of mesenchymal cell biology and alveolar formation during lung development.
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Pulmão/embriologia , Mesoderma/citologia , Miofibroblastos/citologia , Células-Tronco/citologia , Animais , Diferenciação Celular/fisiologia , Feminino , Perfilação da Expressão Gênica , Pulmão/citologia , Mesoderma/metabolismo , Camundongos , Miofibroblastos/metabolismo , Gravidez , Transdução de Sinais , Células-Tronco/metabolismoRESUMO
Wnt signaling is critical for cell fate specification and cell differentiation in many organs, but its function in pulmonary neuroendocrine cell (PNEC) differentiation has not been fully addressed. In this study, we examined the role of canonical Wnt signaling by targeting the gene for Adenomatous Polyposis Coli (Apc), which controls Wnt signaling activity via mediating phosphorylation of beta-catenin (Ctnnb). Targeting the Apc gene in lung epithelial progenitors by Nkx2.1-cre stabilized Ctnnb and activated canonical Wnt signaling. Apc deficiency altered lung epithelial cell fate by inhibiting Clara and ciliated cell differentiation and activating Uchl1, a marker of neuroendocrine cells. Similar to PNEC in normal lung, Uchl1(positive) cells were innervated. In mice with targeted inactivation of Ctnnb by Nkx2.1-cre, PNEC differentiation was not interrupted. These indicate that, after lung primordium formation, Wnt signaling is not essential for PNEC differentiation; however, its over-activation promotes PNEC features. Interestingly, Nkx2.1 was extinguished in Apc deficient epithelial progenitors before activation of Uchl1. Examination of Nkx2.1 null lungs suggested that early deletion of Nkx2.1 inhibits PNEC differentiation, while late repression does not. Nkx2.1 was specifically inhibited in Apc deficient lungs but not in Ctnnb gain-of-function lungs indicating a functional difference between Apc deletion and Ctnnb stabilization, both of which activate Wnt signaling. Further analysis revealed that Apc deficiency led to increased TGF-beta signaling, which inhibited Nkx2.1 in cultured lung endodermal explants. In contrast, TGF-beta activity was not increased in Ctnnb gain-of-function lungs. Therefore, our studies revealed an important mechanism involving Apc and TGF-beta signaling in regulating the key transcriptional factor, Nkx2.1, for lung epithelial progenitor cell fate determination.
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Proteína da Polipose Adenomatosa do Colo/fisiologia , Células Epiteliais/citologia , Pulmão/citologia , Proteínas Nucleares/fisiologia , Fatores de Transcrição/fisiologia , Fator de Crescimento Transformador beta/metabolismo , Animais , Diferenciação Celular , Linhagem da Célula , Deleção de Genes , Regulação da Expressão Gênica no Desenvolvimento , Genes APC , Pulmão/embriologia , Camundongos , Modelos Biológicos , Morfogênese , Proteínas Nucleares/genética , RNA Mensageiro/metabolismo , Transdução de Sinais , Células-Tronco/citologia , Fator Nuclear 1 de Tireoide , Fatores de Transcrição/genéticaRESUMO
INTRODUCTION: Atherosclerosis, traditionally considered a lipid-related disease, is now understood as a chronic inflammatory condition with significant global health implications. OBJECTIVES: This review aims to delve into the complex interactions among immune cells, cytokines, and the inflammatory cascade in atherosclerosis, shedding light on how these elements influence both the initiation and progression of the disease. METHODS: This review draws on recent clinical research to elucidate the roles of key immune cells, macrophages, T cells, endothelial cells, and clonal hematopoiesis in atherosclerosis development. It focuses on how these cells and process contribute to disease initiation and progression, particularly through inflammation-driven processes that lead to plaque formation and stabilization. Macrophages ingest oxidized low-density lipoprotein (oxLDL), which partially converts to high-density lipoprotein (HDL) or accumulates as lipid droplets, forming foam cells crucial for plaque stability. Additionally, macrophages exhibit diverse phenotypes within plaques, with pro-inflammatory types predominating and others specializing in debris clearance at rupture sites. The involvement of CD4+ T and CD8+ T cells in these processes promotes inflammatory macrophage states, suppresses vascular smooth muscle cell proliferation, and enhances plaque instability. RESULTS: The nuanced roles of macrophages, T cells, and the related immune cells within the atherosclerotic microenvironment are explored, revealing insights into the cellular and molecular pathways that fuel inflammation. This review also addresses recent advancements in imaging and biomarker technology that enhance our understanding of disease progression. Moreover, it points out the limitations of current treatment and highlights the potential of emerging anti-inflammatory strategies, including clinical trials for agents such as p38MAPK, tumor necrosis factor α (TNF-α), and IL-1ß, their preliminary outcomes, and the promising effects of canakinumab, colchicine, and IL-6R antagonists. CONCLUSION: This review explores cutting-edge anti-inflammatory interventions, their potential efficacy in preventing and alleviating atherosclerosis, and the role of nanotechnology in delivering drugs more effectively and safely.
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Improving the efficiency of tin-based perovskite solar cells (TPSCs) is significantly hindered by energy level mismatch and weak interactions at the interface between the tin-based perovskite and fullerene-based electron transport layers (ETLs). In this study, four well-defined multidentate fullerene molecules with 3, 4, 5, and 6 diethylmalonate groups, labeled as FM3, FM4, FM5, and FM6 are synthesized, and employed as interfacial layers in TPSCs. It is observed that increasing the number of functional groups in these fullerenes leads to shallower lowest unoccupied molecular orbital (LUMO) energy levels and enhance interfacial chemical interactions. Notably, FM5 exhibits a suitable energy level and robust interaction with the perovskite, effectively enhancing electron extraction and defect passivation. Additionally, the unique molecular structure of FM5 allows the exposed carbon cage to be tightly stacked with the upper fullerene cage after interaction with the perovskite, facilitating efficient charge transfer and protecting the perovskite from moisture and oxygen damage. As a result, the FM5-based device achieves a champion efficiency of 15.05%, significantly surpassing that of the PCBM-based (11.77%), FM3-based (13.54%), FM4-based (14.34%), and FM6-based (13.75%) devices. Moreover, the FM5-based unencapsulated device exhibits excellent stability, maintaining over 90% of its initial efficiency even after 300 h of air exposure.
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Clara cells, together with ciliated and pulmonary neuroendocrine cells, make up the epithelium of the bronchioles along the conducting airways. Clara cells are also known as progenitor or stem cells during lung regeneration after injury. The mechanisms of Clara cell differentiation are largely unknown. Transforming growth factor beta (TGFbeta)is a multifunctional molecule with roles in normal development and disease pathogenesis. In this study, we deleted the TGFbeta type I receptor Alk5 in the embryonic lung epithelium using Gata5-Cre mice. Absence of Alk5 blocked Clara cell differentiation but had no effect on ciliated or pulmonary neuroendocrine cells. Hairy/Enhancer of Split-1, which is expressed in Clara cell putative ;progenitors' was found to be a downstream target of Alk5 in vivo and in vitro. Loss of Alk5-mediated signaling also stimulated Pten gene expression and inhibited ERK phosphorylation in vivo. Using lung epithelial cells, we show that Alk5-regulated Hes1 expression is stimulated through Pten and the MEK/ERK and PI3K/AKT pathways. Thus, the signaling pathway by which TGFbeta/ALK5 regulates Clara cell differentiation may entail inhibition of Pten expression, which in turn activates ERK and AKT phosphorylation.
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Pulmão/embriologia , Proteínas Serina-Treonina Quinases/fisiologia , Receptores de Fatores de Crescimento Transformadores beta/fisiologia , Mucosa Respiratória/embriologia , Animais , Contagem de Células , Diferenciação Celular/genética , Células Cultivadas , Embrião de Mamíferos , Endoderma/metabolismo , Endoderma/fisiologia , Deleção de Genes , Humanos , Pulmão/citologia , Pulmão/metabolismo , Camundongos , Camundongos Transgênicos , Especificidade de Órgãos/genética , Proteínas Serina-Treonina Quinases/genética , Proteínas Serina-Treonina Quinases/metabolismo , Receptor do Fator de Crescimento Transformador beta Tipo I , Receptores de Fatores de Crescimento Transformadores beta/genética , Receptores de Fatores de Crescimento Transformadores beta/metabolismo , Mucosa Respiratória/citologia , Mucosa Respiratória/metabolismo , Transdução de Sinais , Células-Tronco/metabolismo , Células-Tronco/fisiologiaRESUMO
The airways of the mammalian lung are lined with highly specialized epithelial cell types that are the targets of airborne toxicants and injury. Notch signaling plays an important role in the ontogeny of airway epithelial cells, but its contributions to recruitment, expansion or differentiation of resident progenitor/stem cells, and repair and re-establishment of the normal composition of airway epithelium following injury have not been addressed. In this study, the role of a specific Notch receptor, Notch1, was investigated by targeted inactivation in the embryonic lung epithelium using the epithelial-specific Gata5-Cre driver line. Notch1-deficient mice are viable without discernible defects in pulmonary epithelial cell-fate determination and differentiation. However, in an experimental model of airway injury, activity of Notch1 is found to be required for normal repair of the airway epithelium. Absence of Notch1 reduced the ability of a population of cells distinguished by expression of PGP9.5, otherwise a marker of pulmonary neuroendocrine cells, which appears to serve as a reservoir for regeneration of Clara cells. Hairy/enhancer of split-5 (Hes5) and paired-box-containing gene 6 (Pax6) were found to be downstream targets of Notch1. Both Hes5 and Pax6 expressions were significantly increased in association with Clara cell regeneration in wild-type lungs. Ablation of Notch1 reduced Hes5 and Pax6 and inhibited airway epithelial repair. Thus, although dispensable in developmental ontogeny of airway epithelial cells, normal activity of Notch1 is required for repair of the airway epithelium. The signaling pathway by which Notch1 regulates the repair process includes stimulation of Hes5 and Pax6 gene expression.
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Lesão Pulmonar/metabolismo , Receptor Notch1/metabolismo , Regeneração , Mucosa Respiratória/metabolismo , Transdução de Sinais , Animais , Fatores de Transcrição Hélice-Alça-Hélice Básicos/biossíntese , Fatores de Transcrição Hélice-Alça-Hélice Básicos/genética , Proteínas do Olho/biossíntese , Proteínas do Olho/genética , Regulação da Expressão Gênica/genética , Proteínas de Homeodomínio/biossíntese , Proteínas de Homeodomínio/genética , Lesão Pulmonar/genética , Lesão Pulmonar/patologia , Camundongos , Camundongos Knockout , Fator de Transcrição PAX6 , Fatores de Transcrição Box Pareados/biossíntese , Fatores de Transcrição Box Pareados/genética , Receptor Notch1/genética , Proteínas Repressoras/biossíntese , Proteínas Repressoras/genética , Mucosa Respiratória/lesões , Mucosa Respiratória/patologia , Ubiquitina Tiolesterase/biossíntese , Ubiquitina Tiolesterase/genéticaRESUMO
Evidence suggests epithelial-mesenchymal transition (EMT) as one potential source of fibroblasts in idiopathic pulmonary fibrosis. To assess the contribution of alveolar epithelial cell (AEC) EMT to fibroblast accumulation in vivo following lung injury and the influence of extracellular matrix on AEC phenotype in vitro, Nkx2.1-Cre;mT/mG mice were generated in which AECs permanently express green fluorescent protein (GFP). On days 17-21 following intratracheal bleomycin administration, ~4% of GFP-positive epithelial-derived cells expressed vimentin or α-smooth muscle actin (α-SMA). Primary AECs from Nkx2.1-Cre;mT/mG mice cultured on laminin-5 or fibronectin maintained an epithelial phenotype. In contrast, on type I collagen, cells of epithelial origin displayed nuclear localization of Smad3, acquired spindle-shaped morphology, expressed α-SMA and phospho-Smad3, consistent with activation of the transforming growth factor-ß (TGFß) signalling pathway and EMT. α-SMA induction and Smad3 nuclear localization were blocked by the TGFß type I receptor (TßRI, otherwise known as Alk5) inhibitor SB431542, while AEC derived from Nkx2.1-Cre;Alk5(flox/KO) mice did not undergo EMT on collagen, consistent with a requirement for signalling via Alk5 in collagen-induced EMT. Inability of a pan-specific TGFß neutralizing antibody to inhibit effects of collagen together with absence of active TGFß in culture supernatants is consistent with TGFß ligand-independent activation of Smad signalling. These results support the notion that AECs can acquire a mesenchymal phenotype following injury in vivo and implicate type I collagen as a key regulator of EMT in AECs through signalling via Alk5, likely in a TGFß ligand-independent manner.
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Células Epiteliais Alveolares/patologia , Colágeno Tipo I/farmacologia , Transição Epitelial-Mesenquimal/efeitos dos fármacos , Proteínas Serina-Treonina Quinases/metabolismo , Fibrose Pulmonar/patologia , Receptores de Fatores de Crescimento Transformadores beta/metabolismo , Actinas/metabolismo , Células Epiteliais Alveolares/efeitos dos fármacos , Células Epiteliais Alveolares/metabolismo , Angiotensina II/metabolismo , Animais , Antibióticos Antineoplásicos/toxicidade , Benzamidas/farmacologia , Bleomicina/toxicidade , Células Cultivadas , Dioxóis/farmacologia , Modelos Animais de Doenças , Feminino , Ligantes , Masculino , Camundongos , Camundongos Knockout , Proteínas Serina-Treonina Quinases/antagonistas & inibidores , Fibrose Pulmonar/induzido quimicamente , Fibrose Pulmonar/metabolismo , Receptor do Fator de Crescimento Transformador beta Tipo I , Receptores de Fatores de Crescimento Transformadores beta/antagonistas & inibidores , Transdução de Sinais , Vimentina/metabolismoRESUMO
BACKGROUND: Non-alcoholic fatty liver disease (NAFLD) is the most prevalent cause of chronic hepatic disease and results in non-alcoholic steatohepatitis (NASH), which progresses to fibrosis and cirrhosis. Although the Leptin deficient rodent models are widely used in study of metabolic syndrome and obesity, they fail to develop liver injuries as in patients. METHODS: Due to the high similarity with humans, we generated Leptin-deficient (Leptin-/-) pigs to investigate the mechanisms and clinical trials of obesity and NAFLD caused by Leptin. RESULTS: The Leptin-/- pigs showed increased body fat and significant insulin resistance at the age of 12 months. Moreover, Leptin-/- pig developed fatty liver, non-alcoholic steatohepatitis and hepatic fibrosis with age. Absence of Leptin in pig reduced the phosphorylation of JAK2-STAT3 and AMPK. The inactivation of JAK2-STAT3 and AMPK enhanced fatty acid ß-oxidation and leaded to mitochondrial autophagy respectively, and both contributed to increased oxidative stress in liver cells. In contrast with Leptin-/- pig, although Leptin deletion in rat liver inhibited JAK2-STAT3 phosphorylation, the activation of AMPK pathway might prevent liver injury. Therefore, ß-oxidation, mitochondrial autophagy and hepatic fibrosis did not occurred in Leptin-/- rat livers. CONCLUSIONS: The Leptin-deficient pigs presents an ideal model to illustrate the full spectrum of human NAFLD. The activity of AMPK signaling pathway suggests a potential target to develop new strategy for the diagnosis and treatment of NAFLD.
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Epithelial-mesenchymal interaction is required for normal growth, morphogenetic patterning, and cellular differentiation in developing lungs. Various signaling pathways have been defined in establishing the patterning of this branched organ. The phosphoinositide-3-kinase (PI3K) signaling plays an important role in disease pathogenesis but remains largely uncharacterized in embryonic development. In this study, we activated a specific catalytic subunit of PI3K catalytic enzymes, Class IA p110α (p110α), in the embryonic lung mesenchyme using the Dermo1-Cre mouse. Activation of p110α promoted branching morphogenesis and blocked club cell differentiation in both proximal and distal airways. Mechanistically, the LIM homeodomain gene Islet-1 (Isl1), fibroblast growth factor 10 (Fgf10), and SRY (sex-determining region Y)-box9 (Sox9) were found to be downstream targets of p110α. The significantly increased expressions of Isl1, Fgf10, and Sox9 resulted in the stimulation of branching in mutant lungs. Activation of p110α-mediated signaling also increased the expression of phosphatase and tensin homolog deleted on chromosome 10 (Pten) and hairy/enhancer of split 1 (Hes1), which in turn blocked club cell differentiation. Thus, the signaling pathway by which PI3K/p110α-regulated epithelial-mesenchymal interactions may entail Isl1-Fgf10-Sox9 and Pten-Hes1 networks, which consequently regulate branching morphogenesis and club cell differentiation, respectively.
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Adenomatous polyposis coli (Apc) is critical for Wnt signaling and cell migration. The current study examined Apc expression during lung development, injury, and repair. Apc was first detectable in smooth muscle layers in early lung morphogenesis, and was highly expressed in ciliated and neuroendocrine cells in the advanced stages. No Apc immunoreactivity was detected in Clara or basal cells, which function as stem/progenitor cell in adult lung. In ciliated cells, Apc is associated mainly with apical cytoplasmic domain. In response to naphthalene-induced injury, Apc(positive) cells underwent squamous metaplasia, accompanied by changes in Apc subcellular distribution. In conclusion, both spatial and temporal expression of Apc is dynamically regulated during lung development and injury repair. Differential expression of Apc in progenitor vs. nonprogenitor cells suggests a functional role in cell-type specification. Subcellular localization changes of Apc in response to naphthalene injury suggest a role in cell shape and cell migration.